ES2308291T3 - DEVICE OF A TAPON OF TEST. - Google Patents

Abstract

A device is described for a plug (12) for pressure testing of bore holes and the like in a formation or the like, and associated pipe (10) in which the plug is installed in a plug-carrying chamber (14), and the plug (12) seals the passage through the pipe by cooperating with sealing bodies (23, 25), with the underside of the plug (12) being arranged (rests) in a seat at the bottom of the chamber. The plug is characterized in that it comprises a number of layer-formed or tier-formed ring disc elements of a given thickness, on fitted on top of the other.

Description

Device of a test plug.

The present invention relates to a device of a test plug as described in the introduction of the claims shown below. Such plugs are currently used in wells such as wells of oil and gas and in water wells.

The invention also relates to different realizations of devices for the construction of pipes adapted to accommodate such a glass stopper.

It is known as using plugs of a material that it can disintegrate or it can break, such as a material ceramic or glass It is also known as using composite plugs that can withstand pressure only in one direction. This is knows that it is used, for example, in the United States.

It is well known that production wells in the oil industry have to be tested before it start using One of these trials refers to verifying that well components can withstand the pressure under which They must work during oil / gas production. To do said tests a plug is inserted that closes the passage in the well. Supplying pressure from the surface with the help of a fluid adequate can be checked over time that the well is sufficiently impermeable to water against losses. Previously it They used plugs that were removed after use. Lately it has it was desirable to use plugs that do not have to be removed again after use That is, plugs that could open, break or dissolve after they had been used.

Solutions are also previously known in the that all or parts of the cap are manufactured from rubber, and where a section comprises a chemical agent that dissolves the plug rubber when the test is complete and you want to remove the cap. However, this method would be too uncertain and slow in floating platform operations, considering the high operating costs for said platform, since it is needed know the exact moment at which the cap is removed and the He passed. The drilling tower cannot leave the well before that the cap and the solution mentioned are opened You may need days before. This type of plug has been subsequently replaced by plugs that can break.

As examples of known breakable plugs are refers to U.S. Patent Application No. 5,607,017 and United States Patent Application 2003 / 0168214A (based on Norwegian Patent Application 2000 1801).

You can also use a TDP PLUG (= Disappearing tube) to safeguard the well against situations blowout and also to adjust the equipment activated by Pressure in a safe way. Otherwise there is a risk that The fluid comes out of the well. In practice, the plug fits into the shape of a TDP plug at the bottom of a pipe production / pipe. The pipes are subsequently screwed between yes and they are guided down into the well until the plug reaches the correct depth

The test cap is placed in a seat properly adapted in the pipe / pipe and systems are used gasket to get a sufficient seal against the wall of the surrounding internal pipe. The seals are placed in a hole adapted in the inner wall of the pipe and the seal against the Stopper is placed radially inside in your seat.

As an example, a glass plug that can be adjust (or direct) as a unit by itself, that is, without permanently set in a pipe. These will be plugs that they are introduced into the well with pipes by means of a wire or with coils A plug of this type will be hollow, that is, it will have a through hole and will often be equipped with an external joint which can form a grip against the inner wall of the well, the called covers and with a glass plug fixed in the plane lower. The complete unit, the "bridge plug" is descends to a desired depth, expands to provide sufficient grip and seal and to provide a seal during the test or to stop a possible release of Water.

In this document, the user can also remove the glass in the cap with explosives or blowouts / impacts thus avoiding having to remove the cap again. Is a known problem that plugs can be difficult to remove, especially if they have remained in the well for a while dragged on.

An important aspect for this type of use of plugs is that the glass plug can withstand rapid changes of temperature. With the use of the wire system, the descent to the full depth with the resulting elevated temperature can be quick

The new glass stopper that is divided into layers is much better with respect to rapid heating than previously known solutions, such as in the solution of Norwegian patent mentioned above 2000 1801 (belonging to the applicant). In this document, the glass is in a piece and can often be damaged by rapid heating such as A consequence of internal stress.

The use of ceramic or glass materials such as material in such caps is well known, as shown, by example, in the aforementioned Patent Application 2000 1801. In In general, glass is very suitable as a stopper material for oil industry It is practically inert to all types of chemical agents and it is safe for personnel who can handle the plug. In addition, the glass retains its strength at elevated temperatures and can remain in an oil well for a very long time prolonged without damaging or structurally degrading.

Ceramic / glass plugs comprise a explosive charge that detonates when the tests are completed, of such that the plug breaks and the passage opens to release the flow. The advantage with such a break is that the ceramic material or the glass breaks up to small particles that just removed by washing the well without leaving any remains that may be harmful. Such explosive charges have been incorporated normally in the cap itself, in which one or more cuts / holes to place the explosive charge on the part top of the cap. However, this leads to a weakening of the structure of the cap since they can arise easily stripes and fissure formations in the glass when exposed to high pressures or pressure variations during tests Preparatory

At the same time, the industry wants to be able of using higher work pressures in production wells. In our essays have established that previous versions of such plugs do not have sufficient strength or safety with regarding the number of load alterations, changes in the address of load and temperature fluctuations. Users too demand plugs to constantly increase the pressures of job. Well technology development implies that Currently, plug constructions have to be provided which they can withstand pressures of up to 1000 bars, so that can apply in modern high pressure wells.

It has been observed that the shape of the material that is can break and the composition of the plug itself are vital importance for the pressure the plug resists.

There are also valves and other systems currently in the market that perform the same function as the plugs that can be broken, for example, with flaps or keys that they can be opened, but these have obvious advantages: they are technically complicated, they have many moving parts and incorporate Many possibilities of defects. They can be sealed simple by sediment / particles that enter the mechanisms. Such valves as a consequence are expensive and therefore in the Most cases are omitted or rejected.

Based on the above, it is a purpose of the invention provide a new plug construction that exceeds the disadvantages mentioned above, that is, a construction that can withstand higher pressures during test procedures, rapid temperature oscillations and many and varied load changes. It is an objective of the present invention provide a plug construction that can meet the demands mentioned above with Regarding plugs.

The construction of a plug according to the invention is characterized by the characteristics indicated by the features in the claim shown below 1. Preferred embodiments are presented in the dependent claims.

The device for the tube section is like is described in claim 22 and in the claims Dependents 23-25.

With the present invention the following features: a stronger plug is obtained comprising a series of layers with layers of glass. The construction is such that the glass can withstand several load changes and major changes of load variables that previously known plugs, that is, can resist pressure changes between pressure above or pressure by below.

The glass is divided into functions in such a way which plates / discs of one type of disc can guarantee the seal hydraulic against a liquid or gas under pressure at which it is exposed the plug, while another type of plate / disk works to admit the load that arises as a result of the pressure Against the glass area.

A series of essays has clearly shown that this division of labor exerts less effort on glass than if the disc made both the seal and if it handled it Charge time.

During special operations, such as explosive drilling just above the glass stopper it is also important to use several layers of glass necessary to resist the considerable pressure shocks that this kind of Work causes well.

Layering the cap into plates / discs and the possible laminate between each plate / disk leads to a much greater tolerance against temperature changes fast than plugs that are previously known. This was a great problem with previously known technology.

Layering and modular construction ensure that a plug can be produced that conforms to environment conditions (pressure, temperature, etc.) that are expected in the well in which the plug has to be used. Of course it They take into account safety margins. Therefore, you can adjust and specially build the cap according to the customer pressure requirements. For example, you can produce a 1000 bar plug with 6-8 layers of glass while a 300 bar plug can comprise 2 to 4 layers.

It is important that the glass hardens in such a way form that can be broken, that is, by mechanical breakdown, at the same time that retains its strength. The hardening is done by glass heat treatments.

The invention will be explained below with more detail with reference to the attached figures in which:

Figure 1 shows a general diagram of the construction of a cap according to the invention, placed in a pipe / production pipe, where a hole is made of purge through the surrounding pipe wall.

Figure 2 shows an alternative embodiment of the plug, that is, for the number of layers in the plug.

Figure 3 shows a variant of the cap that mentioned above and comprising an explosive charge in a separate glass section.

Initially reference is made to Figure 1 showing a pipe of type 10 production pipe previously known and in which a plug 12 is fixed. The plug 12 is placed in a radially directed enlarged section 14 of the pipe 10. Section 14 has an internal diameter slightly greater than the rest of the pipe to provide placement safe of the cap and to avoid the limitation of the cutting area cross flow when the cap is removed. The plug 12 is mainly cylindrical (even without other forms of cutting Transverse can be adapted to the cross section of the pipe 10).

The bottom side 16 of the cap 12 forms a seat 18 with annular shape, inclined, with shoulder shape on the bottom of the section enlarged in relation to the axis longitudinal X of the pipe 10. The top of the plug It also has an inclined surface. Thus, the plug is more able to withstand high pressures and pressure pulses. He contact angle of the plug 10 against the seat is approximately 45º.

The augmented section 14 is designed in such a way way that does not prevent operation and subsequent maintenance from the well. In addition, the diameter of the plug section does not have to be too big since this can lead to the operator (the oil company) have to use pipes from cover / cladding with an internal diameter correspondingly higher. Since casing pipes can have lengths 10 kilometers and more, a plug section that is too much thick could lead to additional costs for the operator.

The gasket construction of the plug 23, 25 in the internal wall forms a seal between the glass disk 32, 34, which is located just above and just below the chamber of cap support pipe 14 and the inner wall of the pipe. These glass discs are also indicated with 32, 34 and are arranged for the sealing function itself.

This provides a diminished load of the own glass plug 12 and the plug section can be done more narrow and thereby reduce the diameter requirement of the casing pipe and the production pipe. Stopper 12 it is shaped like a cylinder and with several glass discs 13 in the center with a larger diameter than the formation glass discs of seal 32, 34.

The new plug construction according to the invention is characterized because it is presented as a construction formed of layers or levels where one of the layers is placed on the top of the next layer. This can be seen in the figures.

The layers indicated with Z are manufactured as Ring-shaped disk plate elements with a given thickness. In each end of the central cylindrical section 13 of the plug 12, the inclined plates 15, 17 fit, also indicated with Y in the figure. At each end of the cap, the mentioned terminal disks 32 and 34 are mounted, indicated by X in the figure, which together with the O-rings 23, 25 fixed peripherally form the seal of plug against the inner wall of the pipe 10, this is to avoid losses.

As a consequence, the cap according to the Invention can be manufactured with a required number of layers. From according to a particularly preferred embodiment, a layer of a different glass material is placed between the different layers in the cap. This is to get better protection from glass with respect to impact on handling and also so that the Cap be able to withstand higher pressures.

As an example of an inserted layer or film inserted, you can use a plastic film, a film of felt, a paper film or similar material.

The inserted layer works like a laminate, for strength and / or as a means of sliding and as an absorber of impact. Alternatively, the glass plates can be joined by rolling with a bonding agent such as a glue.

Through the use of pressure hardening, The glass can become brittle. And with the right tempering (preprocessing), the glass gets strength, rigidity and good breaking characteristics.

To obtain a satisfactory seal, enter each glass disk and between the outer surfaces of the glass and The inner wall of the pipe, the glass can be polished. This means that the glass plate is manufactured as frosted glass (Norwegian: "slip"). This provides a good fit between the glass and metal, that is, a satisfactory seat between each glass plate and between the outer surface of the glass and metal of the internal pipe wall.

To simplify industrial production and to provide a simpler adjustment and the best possible performance an equilibrium hole 36 is drilled from the center of the plug and radially through the pipe or pipe section 10/14 in the one that puts the cap 12. The hole 36 is drilled radially into the center of the enlarged section 14. When the two glass plates 15a, 15b upper and lower, respectively, see Figure 2, during the adjustment of the plug 10 at work guide approaching each other to stand supporting each other to what along the edge line 38, the air will be purged outside to through hole 36 in the wall of the pipe 10 as a consequence of the narrow passage.

Hole 36 offers a secure adjustment of the parts of the inner layer plug together. Without this hole, the entire plug should have been adjusted in a vacuum to avoid a large overpressure between the glass discs when they come together and this would be complicated and expensive and the plugs would not work optimal way. This hole 36 is also used to balance the pressure on the glass surfaces when the plug 6 is placed Down in the well.

The balancing hole 36 on the cover It also works to decrease the pressure load on the plug. Without balancing this type through hole 36 you could end up exceeding the pressure range or the limit of cap tolerance. This is because the pressure in the inside the glass stopper between the discs is initially atmospheric (1 bar absolute pressure). But when he plug fits at depths of 2-3 km and the well it is filled with water in the test phase, hydrostatic pressure It will only reach 2-300 bars. In addition comes the test pressure that is typically 350 bars in a well conventional. Yet you can have a pressure difference of 300 + 350 = 650 bars for glass discs in which Initially there is atmospheric pressure. Using hole 36 as a vent hole or unidirectional valve, as has been mentioned in the previous paragraph, then you can balance the hydrostatic pressure and decrease the differential pressure up to only the test pressure, that is, a pressure of 350 pubs.

According to a preferred embodiment, the glass stopper is placed in a seat or a so-called "cradle"  37 of a higher quality material, softer. This material is preferably a metal such as bronze. As shown in the Figure 3, the seat 17 has a shape corresponding to the outer peripheral side surface of the enlarged section of the stopper 13, so that it can be positioned constant in the increased section of the pipe. This solution It will safeguard the plug against damage by rough treatment, by example, during lifting with cranes and the like, before the section fit in pipe section 10. The same cradle 17 is can use as a support and a receptacle for the forces that exert pressure against the glass area. This force can be, for example, 150 tons. This means that the glass remains in the cradle which in turn remains against the section of surrounding tube.

The glasses are polished and preferably they conform differently depending on their function, where a type of glass can constitute the pressure seal (17-18), while another type handles the load that It is exerted by fluid pressure.

As you can see initially, the plug glass can be removed with the help of an explosive charge including 40 that attaches to the glass or inside the cover of the plug. An embodiment is shown in Figure 1 where loads explosives 40 are fixed inside a separate glass disk dedicated 42 that sits on top and near the seal terminal plate 32. This disk 42 is called an anchor For the explosive charge. When disk 42 explodes, the plug glass breaks completely when the anchor of the disc 42 It also breaks completely.

With respect to the detonation of the cap itself, this can happen by remote control from the surface with the help of a controlled pump pressure provided by the use of the oil rig pumps. Can also be used timers to detonate and remove the cap after intervals Temporary default.

The manufacture of the tube section that can containing a plug 12 of this type is done before a work of assembly This means that the plug can be assembled in modules with appropriate qualities of materials, etc., to meet different needs depending on the conditions in the location of use It also means that the length of the plug It can be adjusted easily by varying the number of plates glass that are placed in the stack to make the cap.

Figures 1 and 2 show two constructions different. Figure 1 shows a plug with four plates of type Z glass, while Figure 2 shows a stopper with only two glass discs of type Z. Figure 1 also shows the additional explosive glass disk 42 while the cap according to Figure 2 does not have this type of load explosive

When the glass plug explodes subsequently and the pipe has been opened for fluid flow, This section of shorter pipe remains in the pipe. After You can use the section later to install and contain mechanically actuated plugs for other tests or for Safeguard the well.

A shoulder called is implemented "No-Go", which is shown herein by reference number 46, on the cap cover. This is shown by reference number 46 in Figure 2. The shoulder is shaped like a fold 46 turning inwards shaped like a ring or partition in the pipe. It will not disturb the flow in the pipe to a large extent nor will it obstruct the equipment that subsequently you must descend beyond the section of plug.

Shoulder 46 can be used to fix plugs mechanics that descend later in the pipe. A plug which has an internal diameter approximately the same as the pipe and that descends, it will rest with its lower side on the called shoulder "No-Go" 46. With this form of shoulder 46 it is possible to fix a "wire technology plug" to this seat This anchor is often called an equipment That is on hold. This means that in performances tampons or other equipment can be placed after the well in the same recess, in which the glass plug was installed originally and establish a secure anchor and a function of seal in this area. This prevents the equipment Shoulder section pass 46.

Figure 3 shows this variant in the form of an explosive fixation 40 on disk 42 and a so-called shoulder No-Go 46 at the bottom to place caps with wire technology After the glass has been removed, such plugs can be removed towards the No-Go and they can place in that place without control of the previous depth and adjust to anchor or stay against shoulder 46. After this, the well can be safeguarded with this plug for work or for the rehearsal

In addition, both figures 2 and 3 show the embodiment with the radially elongated central section 15 of the cap unit 13 (which is formed by the two glass discs upper and lower 13, respectively) that are placed against the inclined seat 18 in the pipe wall.

Claims (25)

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1. A device for a breakable plug (12) arranged for a pressure test of a drill hole in a formation or the like and said plug being installed in a plug holder chamber (14) of a pipe in said drill hole, characterized in that the plug seals the passage through the pipe (10) cooperating with seal bodies, since the bottom side (16) of the plug is arranged in a seat (18) at the bottom of the chamber, the plug comprising several glass annular disk elements (13, 32, 34) in the form of a layer or in the form of a level of a given thickness, one fixed on top of the other, and a film or sheet of a material Different glass is inserted between the different layers of the cap to obtain the strength and stiffness required. 2. The device according to claim 1, characterized in that the inserted film comprises a plastic film, a felt film, a paper film or the like. 3. The device according to claims 1-2, characterized in that the glass discs are laminated together with a bonding agent such as a glue. The device according to any of the preceding claims, characterized in that the glass discs are hardened or brittle in such a way that a simple and effective mechanical breakage of the glass is obtained. 5. The device according to any of the preceding claims, characterized in that the glass is formed with a polished surface to obtain a satisfactory seal between each glass disk and between the external surfaces of the glass and the metal of the internal wall of the pipe . The device according to any of the preceding claims, characterized in that the glass stopper is placed in a frame or a cradle of a high quality, softer material (37) such as, for example, of a softer metal such as bronze to safeguard the plug against damage by rough treatment. The device according to any of the preceding claims, characterized in that one type of glass (32, 34) takes into account the pressure seal while another type of glass (16, 15) handles the pressure load as a consequence. of liquid pressure. The device according to any of the preceding claims, characterized in that the glass plug is arranged to be removed with the help of an explosive charge (40), which is fixed to the glass on or on the inner side of the cap cover / pipe section. The device according to claim 8, characterized in that the explosive charge of the glass stopper is disposed inside a separate glass disk (42) that is placed on top of and near the seal terminal disk ( 32). 10. The device according to any of the preceding claims, characterized in that several layers (X) are manufactured as disc-shaped plates and also upper and lower inclined plates (15, 17, Y) and also because they are placed at each end of the plug there are terminal sections (32, 34) comprising their own sealing bodies comprising an O-ring (23, 25) that forms the seal of the plug against the inner wall of the pipe (10) to avoid losses. The device according to any of the preceding claims, characterized in that the chamber (30) forms a corresponding inclined seat (18) for a reciprocally shaped upper side of the cap having an angle of contact with the seat of approximately 45º. 12. The device according to any of the preceding claims characterized in that seal bodies (23, 25) are arranged in connection with the inner wall of the pipe (10) above (upstream) and / or below (downstream ) of the chamber (30) and are arranged to form a seal against the respective cylindrical extensions (32, 34) of the cap body (10) above and / or below the chamber. 13. The device according to claim 12, characterized in that each sealing body comprises a seal such as, for example, an O-ring (23, 25) that fits in the ring-shaped recesses in the inner wall of the pipeline. 14. The device according to any of the preceding claims, characterized in that a separate section is divided into two separate sections each containing an explosive charge. 15. The device according to any of the preceding claims, characterized in that the cap cover comprises a "No-Go" shoulder permanently located in the form of a fold or (partition) directed inwardly in the form of a ring ( 40) in the pipeline to be able to easily place mechanical plugs to perform the test or subsequently safeguard the well.

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16. The device according to any of the preceding claims, characterized in that the glass hardens in a way that makes it breakable, also by mechanical breakage, and at the same time retains its strength since the hardening is preferably by heat treatment of the glass. 17. The device according to any of the preceding claims, characterized in that the tube / cover section or the glass fastener is formed with a drain hole (36) to simplify the installation of the glass discs. 18. The device according to any of the preceding claims, characterized in that the hole (36) is used to balance the pressure in order to decrease the pressure load on the plug. 19. The device according to any of the preceding claims, characterized in that a recess for the glass is made in such a way that equipment can be easily directed through it after the glass stopper has been removed, of such so that the corners and the shape conform so that the tools are not trapped. 20. The device according to claim 19, characterized in that the recess (14) for the glass can be used to place caps or other equipment after the glass has been removed, for example, in subsequent operations of the well. 21. The device according to any of the preceding claims 19 or 20, characterized in that the recess (14) for the glass and the surrounding area is formed such that plugs or other equipment can be placed in the same recess and establish both anchor as a seal in this area in subsequent operations of the well. 22. A device for a pipe section for removing a plug, characterized in that it is formed with any of the preceding claims. 23. The device according to claim 22, characterized in that the cap cover comprises a "No-Go" shoulder permanently located in the form of a ring-shaped fold or "partition" (40) directed inwards. in the pipe to simplify the placement of mechanical plugs to perform tests or subsequently safeguard the well. 24. The device according to claim 23, characterized in that the recess (14) for the glass and also the shoulder section (46) are used to place caps or other equipment after the glass has been removed, for example, in subsequent operations of the well. 25. The device according to any of the preceding claims 23-24, characterized in that the recess (14) for the glass and also the shoulder section (46) and the surrounding area is formed such that plugs or other equipment in the same recess and establish both anchor and seal in this area for subsequent operations of the well.